1. Field of the Invention
The invention relates to a device for decoding encoded digital signals corresponding to n types of data of a distinct nature and multiplexed in conformity with the standard referred to as MPEG2 system, comprising particularly an input stage for receiving and storing said data and a communication bus with an external memory.
The field in which this invention is used is constituted by "multimedia" applications in which the decoder can receive data relating to different contexts (video, audio, graphic, etc.) but which are received by the same transmission unit. First of all, these data have been multiplexed in accordance with the MPEG2 system standard (described in the document ISO/IEC JTC 1/SC 29 published on Apr. 27, 1995 by the International Standardization Organization ISO and entitled "Revised text for ITU-T Recommendation H.222.0/ISO/IEC 13818-1, Information Technology--Generic coding of moving pictures and associated audio information: Systems"). The invention particularly relates to the way in which these multiplexed data are received and in which they are demultiplexed before being transmitted to a storage unit for subsequent processing.
2. Description of the Related Art
The textbook "VLSI Implementation of MPEG decoders", T. Fautier, ISCAS '94, London, May 1994, chapter 3.22, pp. 164-172, describes an MPEG decoding configuration intended to receive compressed video data and comprising, at the input, a memory write stage consisting of two flipflop storage units. While one of these units receives the compressed stream of data and is being filled, the other re-transmits the data previously received and, once it is empty, receives in its turn the stream of input data, during which the first unit re-transmits, and so forth. When such a decoder is capable of receiving data relating to different contexts, it should comprise as many pairs of flipflop storage units as there are different contexts (or different types of data to be controlled).